Side dressing has been made fun again by running the Yetter magnum. I used to run two 13 shank machines and I thought soil type had more to do with it not sealing than speed and rate. The high speed Coulter unit like the magnum actually works better in firmer conditions. They will seal in loose conditions but have a tendency to bulldoze. They are high maintenance and not real cheap to fix. I also bought used units that only ran one year before needing rebuilt. Hopefully they will last longer now that they are rebuilt. I run a 13 unit toolbar on 30” and a 6 unit toolbar on 60”. I like the 30” better but just my preference.